Phenotyping And Gene Mapping Of Floral Stem Cell Mutant Ags16 In Arabidopsis Thaliana

The termination of floral stem cell maintenance includes two key transcription factors,WUSCHEL(WUS)and AGAMOUS(AG).WUS can promote the peripheral cell proliferation by maintaining stem cell potential.AG can terminate the activity of stem cells by negative regulation.WUS expression in a direct or indirect manner.The maintenance and termination of WUS expression during the development of floral stem cells is a very complex process and the regulation mechanism remains unclear.In order to identify new floral stem cell regulators and promote the clarification of the regulation mechanism,we screened mutants with weak floral stem cell defects mutants and long siliques from the EMS mutagenesis progeny of ag-11 mutant,carried out systematic phenotyping and gene mapping.The main results are as follows:1.From the EMS mutagenesis progeny of ag-11 mutant we screened a mutant with weak floral stem cell defects and named it as ags16.Compared with ag-11,ags16 mutant is shorter and shows late flowering phenotype.ags16 also has more rosette leaves,cauline leaves,sepals,petals and stamens,but the number of carpels is reduced.The siligues are longer and the number of seeds is increased significantly.2.ags16 has a single recessive mutation and the mutatation is located at chromosome 5,the mutation gene is AT5G08450(HDC1).Bioinformatic analysis shows that the expression of HDC1 gene in the inflorescence meristem and early seed was the highest,the expression is higher in flower organ,the expression is the least in rosette leaves.HDC1 encods a protein with 918 amino acids,the protein is a hydrophilic protein and has poor instability,the irregular curly is the largest proportion of the total population.It has no transmembrane structure and located in the nucleus.HDC1 of Arabidopsis has the highest similarity of Camelina sativa HDC1 according to the phylogenetic analyses.HDC1 also participates in histone deacetylation modification.3.We separated HDC1 single mutant ags16 s by crossing ags16 with Ler.Compared with Ler,ags16 s is shorter and shows late flowering phenotype.ags16 s also has more rosette leaves,cauline leaves,sepals and petals.The siliques are slender,but the number of stamens and carpels shows no difference.4.We separated the ags16 mutant with pWUS: GUS reporter gene from F2 progeny by resistance screening,PCR identification and GUS staining.It can be used for further paraffin section to observe the expression of WUS.